The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 30, 1983
Filed:
Jan. 21, 1982
William L Whaley, Houston, TX (US);
ACF Industries, Incorporated, New York, NY (US);
Abstract
A seat assembly for an expanding gate valve comprising an outer loose fitting main ring (31) with a resilient face seal (41) for sealing against an expanding gate assembly which is mounted in a valve chamber (11) and an inner auxiliary ring (44) fitting loosely in a counterbore recess in the main ring (31) for sealing against the rear wall (35) of a seat pocket (26). An O-ring (61) between opposed surfaces (51, 52) of the rings (31, 44) continuously urges the rings apart and their orientation such that when the gate assembly is expanded in its open and closed positions, the front face (38) of the main ring (31) is flush against the adjacent sealing surface (25) of the gate assembly and the rear face (46) of the auxiliary ring (44) is flush against the rear wall (35) of the seat pocket (26). When the sealing surfaces (24, 25) of the gate assembly are not parallel or there is a misalignment between the gate assembly sealing surfaces and the adjacent valve seat structure, pressurized fluid from the flow passage (12) enters between the rings (44, 31) of the upstream seat assembly. If there is a leak in the downstream seal or the valve chamber is free of flowline pressure, fluid pressure in the flowline forces the rings (31, 44) of the upstream seal assembly into sealing engagement with the gate element (19) and seat pocket wall (35), respectively. In addition, the O-ring (61) is radially expanded and compressed by the fluid pressure to seal between the rings (31, 44). The annular resilient seal (41) in the face (38) of the outer ring (31) is spaced a radial distance from the flow passage (12) which is less than the radial distance of the O-ring (61) from the flow passage (12) and provides a fluid pressure differential area for urging the outer ring (31) to seal against the valve element (19). The seat assembly is intended for upstream sealing but may be used as a downstream seal assembly which seals when the valve is closed by flowline pressure inducing a check valve action of the gate assembly.